<?php 
header('Content-type:text/html;charset=utf-8');
//定义变量**********
//对变量名大小写是敏感的
//$a = 'hdw';
//$A = '后盾网';
//echo $A;


//变量赋值***************
//传值赋值
//$a = 'hdw';
//传址赋值
//$a = 1;
//$b = &$a;
//$b = 2;
//echo $a;


//可变变量
//$a = 'hello';
////$hello = 'world';
//$$a = 'world';
//echo $hello;




















 ?>